Comments on: Gear Clock

By: Alan Parekh

Alan Parekh — Mon, 22 Feb 2010 15:06:20 +0000

Hi John,

We have had lots of inquiries about that, the motor, PCB and electronics will be available as a kit this week.

By: John V

John V — Mon, 22 Feb 2010 14:10:46 +0000

Thanks for the great project. I cut the gears with your gcode and it worked real well. I was not able to locate a motor and was hoping that I might be able to purchase just the electronis and motor. If this is possible let us know. I know there are many cnc folks on various hobby sites that would be interested and it could be a major seller.

By: Wooden Gear Kinetic Sculpture - Hacked Gadgets - DIY Tech Blog

Wooden Gear Kinetic Sculpture - Hacked Gadgets - DIY Tech Blog — Sun, 07 Feb 2010 17:17:56 +0000

[...] have been putting the final touches on the Gear Clock kit which is made up of wooden gears. I have a new appreciation of the effort it takes to make [...]

By: Alan Parekh

Alan Parekh — Sun, 31 Jan 2010 16:03:25 +0000

Hi Dave,

It will when the kit comes out, the new kit controller will work with 48 or 200 step steppers.

By: Dave

Dave — Sun, 31 Jan 2010 14:26:27 +0000

Hey Alan quick question! will a 48 unipolar stepper motor do the job?

By: Alan Parekh

Alan Parekh — Thu, 28 Jan 2010 08:05:24 +0000

Is your 12 volt power supply adjustable? If it is set it for 7 volts. This should be high enough for the voltage regulator (for the chip) to function and will lower the draw from the stepper motor. Where did you see that spec? I don’t think that motor would be from your floppy drive because as you calculated it would be drawing tons of current that I am sure your plug in power supply can’t handle.

If it is truly a 0.7 ohm stepper then you will need to find a different one. The transistors are only rated for between 500 and 600mA tops so they would not handle that current.

Once you get a meter let me know what the actual measurement is.

By: Dave

Dave — Sun, 24 Jan 2010 11:48:54 +0000

Resistance of each coil is 0.7 ohms which i got from a reference data sheet(can’t find the data sheet of my stepper motor), I’ll get a multimeter and get the accurate readings…(stepper motor is a 6v)6v/0.7 Ohms = 8.5714…Amperes??maybe…what if i add around 10 ohm resistors, to the base of the transistors???or do you suggest getting a power transistor…??btw im using an AC/DC adapter for power supply and it is set to 12VDC

By: Alan Parekh

Alan Parekh — Sat, 23 Jan 2010 18:57:20 +0000

How much current is the stepper pulling? When the unit is not stepping (most of the time) it is being held in place by coil 1. In the kit version (which will be released soon) there is a PWM option which will hold the coil with less power.

By: Dave

Dave — Sat, 23 Jan 2010 09:05:53 +0000

Hey Alan,

I got the stepper to work… but the transistor connected to coil 1 overheats, so i removed the connection of coil 1 it started to work, though im not sure of its accuarcy(it does hit the 9 second mark), the diods soldered the correct way, the side without the ring is connected to +12v,so maybe either a faulty resistor or transistor.. any suggestions?

Thnx again

By: Alan Parekh

Alan Parekh — Fri, 22 Jan 2010 16:17:09 +0000

Hi Dave,

Yes, both commons should be tied to pin 1. But since your stepper isn’t 12 volt you will also need to use a resistor in series to allow your stepper motor to operate within its specifications. I would meter the resistance of one of the stepper coils and use a resistor of similar value.